Pulsed microwave photonic vector network analyzer based on direct sampling.

Pulsed VNAs enabling large dynamic measurement at a low pulse duty cycle are necessary for the characterization of active devices due to the overheating damage risk under continuous wave stimulation. In this paper, we proposed a pulsed microwave photonic vector network analyzer (p-MPVNA) based on direct sampling. With the broad system bandwidth of the p-MPVNA and undersampling technique, pulsed signals are received thru asynchronous wideband detection, and pulsed S-parameters are calculated thru vector superposition.

Equalization based inter symbol interference mitigation for time-interleaved photonic analog-to-digital converters.

We present an equalization based inter symbol interference (ISI) mitigation equalization method for time-interleaved photonic analog-to-digital converters (TIPADCs) by modelling the photodetection as a pulse shaper. A zero-forcing equalizer is designed and applied in a single-channel TIPADC system. The periodic ripples in equivalent channel frequency responses under three different photodetection bandwidths are suppressed from ∼2 dB, ∼5 dB, ∼10 dB to ∼0.

Mismatches analysis based on channel response and an amplitude correction method for time interleaved photonic analog-to-digital converters.

A channel mismatch model for time-interleaved photonic analog-to-digital converters is built by decomposing both optical time division multiplexing channels and the wavelength division multiplexing channels into time channels with uniform and equal-amplitude sampling clock. Based on the model, the influence of power and timing mismatch of optical sampling pulse trains, optical sampling pulse temporal shape mismatches, photodetection bandwidth mismatches on the sampling results are analyzed theoretically. Depending on the found relationship between unmodulated components and modulated components, an effective online amplitude mismatch correction method applicable to wideband signals is proposed.